Rockwell Collins (NYSE:COL) took another step into the market for unmanned aerial vehicles (UAVs) on Monday. Spending who-knows-how-much to acquire not-quite-sure-what, the aviation electronics specialist snapped up Warrenton, Va.-based Athena Technologies.

Why all the mystery? Well, one of the benefits of being a private company like Athena is that you don't have to publish your numbers every quarter. And so it doesn't. And so we have to do a bit of guessing today.

What we know
Precious little. We know from its website that Athena manufactures navigation and control systems, primarily for UAVs. We knew that at some recent point in its history, Dun & Bradstreet had Athena pegged at annual revenue in excess of $21 million -- perhaps more.

According to Deloitte & Touche, Athena was one of the "50 fastest growing technology, media, telecommunications and life sciences companies" in Virginia 18 months ago. It won a place on D&T's list by posting "457 percent revenue growth from 2001–2005." (A back-of-the-envelope calculation suggests that this works out to something in the neighborhood of 35% compound annual sales growth.)

We also know that Athena counts Boeing (NYSE:BA) and General Atomics (GA) among its marquee customers. Also on that list are Textron (NYSE:TXT) and Raytheon (NYSE:RTN). General Atomics stands out as probably the most important of these clients, judging from the Pentagon's recently released 2009 budget request. In contrast, conspicuous for its absence from the list is Northrop Grumman (NYSE:NOC), which made out even better than GA in the draft budget. (Northrop may well be a client, by the way. I'm just saying that if it is, I haven't heard them mention it.)

Foolish takeaway
With $4.5 billion in annual revenue already, a couple extra tens of millions from Athena won't move the needle at Rockwell today. But if the new business keeps growing at 35% per year or so, this could easily be a $100 million business unit within five years. What's more, considering Rockwell's scale of operations, and multiple additional clients to pitch on Athena's technology, I wouldn't be surprised to see Rockwell's UAV business grow even faster.

So price considerations aside (which is necessary, because we don't know the price), this looks like a smart buy.

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